Harris Corporation of Melbourne, Fla. has designed a system and method of recording performance of an aircraft engine using a ground data link unit that interfaces with numerous components of the aircraft, including the Digital Flight Data Acquisition Unit (DFDAU), the aircraft Digital Flight Data Recorder (DFDR), and the data multiplexing system commonly referred to as the Full Authority Digital Engine Control (FADEC) for larger jet turbine engines or the Engine Control Unit (ECU) as sometimes referred to with smaller jet turbine engines used on smaller aircraft, including turboprops or other engines generating less than 15,000 pounds of thrust. The term “FADEC/ECU” can be used corresponding to either the term “FADEC” or “ECU” as used by the industry.
An example of this ground data link unit is disclosed in commonly assigned U.S. Pat. No. 6,047,165, the disclosure which is hereby incorporated by reference in its entirety. An engine monitoring system using this ground data link unit is disclosed in commonly assigned U.S. Pat. Nos. 6,148,179 and 6,353,734, the disclosures which are hereby incorporated by reference in their entirety.
In the incorporated by reference '179 and '734 patents, the system and method as disclosed can provide a record of the performance of an aircraft engine by collecting engine data during engine operation, for example, in the ground data link unit, and downloading the collected engine data over a wideband spread spectrum communications signal to a ground based spread spectrum receiver. The signal is demodulated within a ground based spread spectrum receiver to obtain the engine data for further processing. It is also possible to upload data to the ground data link unit, such as algorithms, flight management files, video and entertainment files and other data files.
This Harris Corporation ground data link (GDL) unit is advantageous over prior art systems that took a “snapshot” of basic engine parameters, for example, when the aircraft had lifted to 1,000 feet after initial take-off. The data was limited to one snapshot during flight and was not real-time. These prior art data “snapshots” did not go beyond gross indicators and reactive maintenance techniques. The “snapshots” typically may contain data regarding limited engine parameters (e.g., N1, N2, EGT and Wf) in which the “snapshot” data was recorded either “on board” or downloaded via AGARS using a VHF communication data link. Other monitoring systems required the pilot to enter data manually into a logbook or required removable media such as flash drives and Quick Access Recorders (QAR).
The ground data link unit system disclosed in the incorporated by reference '165, '179 and '734 patents overcomes the drawbacks associated with the prior art “snapshot,” which never gave a true and complete and full flight indication of engine performance during flight of the aircraft. Also, these non-GDL prior art monitoring systems as described not only had data collection of limited value, but also had a high cost for retrieving what may or may not have been the full flight engine data from the aircraft because of limited communication options, for example, limited frequencies and narrow bandwidth/spectrum available from the FCC at the aeronautical frequency spectrum. The overly large engine data files required high bandwidth, e.g., about 10 kbps up to about 36 MB/FLT HR (without compression), which those non-GDL systems could not deliver.
Although the ground data link unit as disclosed in the '165, '179 and '734 patents is a major improvement over prior art engine monitoring systems, the disclosed ground data link unit is typically a large unit installed on the aircraft and interfaces with many airborne systems as previously described. As a result, Harris Corporation developed a Wireless Engine Monitoring System (WEMS) module that monitors aircraft engines in real-time without resorting to the larger ground data link unit that interfaces with many aircraft systems. The WEMS module is disclosed in commonly assigned U.S. Pat. Nos. 6,943,699; 7,456,756; 7,595,739; and 7,755,512, the disclosures which are hereby incorporated by reference in their entirety.
The WEMS module is an engine monitoring module mounted directly on the aircraft engine. It is not installed in the avionics compartment or similar fuselage location, for example, which on the other hand, is the preferred location for the ground data link unit that connects to many airborne units. The WEMS module is interfaced in one example to the Full Authority Digital Engine Controller (FADEC)/Engine Control Unit (ECU) on the engine. The WEMS module is typically small, in one example, about 2×2×4 inches, and can record, store, encrypt and transmit “full flight” engine data. The WEMS module interfaces directly to the FADEC/ECU and records hundreds of engine parameters, for example, with a one second or less sampling frequency. It has a preferred conformal antenna and RF transceiver to download (and upload) data using RF/802.11/cellular techniques, including other spread spectrum techniques as non-limiting examples.
This collection and storage of “full flight” engine data using the WEMS module allows advanced prognostics and diagnostics on the engine and increases engine “time-on-wing” (TOW) and decreases engine maintenance cost per hour (MCPH). The WEMS data is downloaded in one example using a RF/(802.11) spread spectrum/cellular signal to an airport server for processing and/or transported over the internet, PSTN, cellular or other communications network to another workstation for post flight analysis. Data can also be uploaded to the WEMS module, including algorithms for on-board processing. The WEMS module provides an automated wireless solution installed directly on the engine, recording full flight engine data for both large and small turbine engines in large megabyte files and using a high speed data link to extract.
Although the WEMS module operates as an archival data store for full flight engine data, it would be desirable to provide the capability to download in “real-time” significant quantities of engine data during flight and interface with the communications resources commonly available on most international flights. Additionally, it would be desirable to use the WEMS module in a cost effective method to detect and diagnose problems with the most mechanically stressed components within a turbine unit of an aircraft engine. This would require precise monitoring of the rotating subsystems such as the turbine blades and bearing assemblies and gas path parameters such as temperature, vibration, strain and pressure, but would also allow early detection and diagnosis of turbine component faults and help prevent catastrophic failures. There are about forty thousand jet engines worldwide that could be monitored to determine full flight engine data. Thus, to monitor the full flight engine data would increase the efficiency and safety of the engine data.